What is the difference between UniqueID and ClientID?

Answer:

Well, both the properties are associated with asp.net control. The difference is Unique ID has '$' (Dollar) sign and Client ID adds '_' (hyphen) to the control, if master page is used.

Let's say you have placed a text box called 'txtName' in content place holder. So client ID will be ct100_ContentPlaceHolder1_txtName where Unique ID will be ct100$ContentPlaceHolder1$txtName.

ClientID is used to access control in Java Script where using Unique ID you can make a post back using java script __doPostBack() function.

Thanks,
Virendra Dugar